public bool Verify(Abonent sender, Tuple <BigInteger, BigInteger> signedMessage)
{
BigInteger M = signedMessage.Item1;
BigInteger S = signedMessage.Item2;
return(M == BigInteger.ModPow(S, sender.Exponent, sender.N));
}
public void SendKey(Abonent sender, Abonent receiver, BigInteger key)
{
if (!CheckCondition())
{
throw new ArgumentException("p*q > p1*q1");
}
sender.SendKey(receiver, key);
}
public void SendKey(Abonent receiver, BigInteger key)
{
if (key > N)
{
throw new ArgumentOutOfRangeException("Key can't be greater then N");
}
var k1 = BigInteger.ModPow(key, receiver.Exponent, receiver.N);
var s = BigInteger.ModPow(key, this.D, this.N);
var s1 = BigInteger.ModPow(s, receiver.Exponent, receiver.N);
receiver.ReceivedKeyToVerify = new Tuple <BigInteger, BigInteger>(k1, s1);
receiver.ReceiveKey(this);
}
public void ReceiveKey(Abonent sender)
{
if (ReceivedKeyToVerify == null)
{
throw new ArgumentNullException();
}
var k1 = ReceivedKeyToVerify.Item1;
var s1 = ReceivedKeyToVerify.Item2;
var k = BigInteger.ModPow(k1, this.D, this.N);
var s = BigInteger.ModPow(s1, this.D, this.N);
if (!Verify(sender, new Tuple <BigInteger, BigInteger>(k, s)))
{
ReceivedKeyToVerify = null;
throw new ArgumentException("Wrong signification!");
}
KeyFromSender = k;
}
static void Main(string[] args)
{
Abonent a = new Abonent(bitLengthPQ: 256)
{
Name = "Alice"
};
Console.WriteLine(a);
//Abonent b = new Abonent(bitLengthPQ: 256 + 128) { Name = "Bob" };
//Console.WriteLine(b);
//#region ENCRYPTION
//BigInteger serverModulus = BigInteger.Parse("012F740BA9F755D9FC41C703BDB56A4333BBD63E0888C16E0AE5E6265120FEE997", NumberStyles.AllowHexSpecifier);
//BigInteger serverExponent = (int)Math.Pow(2, 16) + 1;
//var publicKey = new Tuple<BigInteger, BigInteger>(serverModulus, serverExponent);
//var messageToEncrypt = BigInteger.Parse("0BBA67B", NumberStyles.AllowHexSpecifier);
//var encryptedMessage = a.Encrypt(publicKey, messageToEncrypt);
//Console.WriteLine("Encrypted for server " + encryptedMessage.ToString("X"));
//#endregion
//#region DECRYPTION
//Console.WriteLine("Enter encrytped message from server: ");
//var bytes = Console.ReadLine();
//var messageToDecrypt = BigInteger.Parse("0" + bytes, NumberStyles.AllowHexSpecifier);
//var decryptedMessage = a.Decrypt(messageToDecrypt);
//Console.WriteLine("Decrypted message on Abonent a " + decryptedMessage.ToString("X"));
//#endregion
//#region VERIFICATION
//var M = BigInteger.Parse("0ffffb111", NumberStyles.AllowHexSpecifier);
//var S = BigInteger.Parse("0352299B5379259F213D1025A354457D81ABAF2D6A71AE77BCD1458EC3D9323E0", NumberStyles.AllowHexSpecifier);
//var signedMessage = new Tuple<BigInteger, BigInteger>(M, S);
//bool verif = a.Verify(publicKey, signedMessage);
//Console.WriteLine("VERIFICATION RESULT " + verif);
//#endregion
//#region SIGNATURE
//var messageToSign = BigInteger.Parse("0FFF123B", NumberStyles.AllowHexSpecifier);
//var signedMessageForServer = a.Sign(messageToSign);
//Console.WriteLine("SIGNED FOR SERVER = ");
//Console.WriteLine("M = " + signedMessageForServer.Item1.ToString("X"));
//Console.WriteLine("S = " + signedMessageForServer.Item2.ToString("X"));
//#endregion
//CryptoSystem rsa = new CryptoSystem(a, b);
//rsa.SendKey(a, b, 999);
//Console.WriteLine(a);
//Console.WriteLine(b);
BigInteger serverModulus = BigInteger.Parse("09EEDBBB30810E2BD60FCBB9B37B7BCE698B8FF3AB035F912552D7E61B12B5A2D", NumberStyles.AllowHexSpecifier);
BigInteger serverExponent = (int)Math.Pow(2, 16) + 1;
var key = BigInteger.Parse("0FFFE", NumberStyles.AllowHexSpecifier);
var publicKey = new Tuple <BigInteger, BigInteger>(serverModulus, serverExponent);
var keyToSend = a.SendKey(publicKey, key);
Console.WriteLine("K1 = " + keyToSend.Item1.ToString("X"));
Console.WriteLine("S1 = " + keyToSend.Item2.ToString("X"));
//-----------------------------------------------------------
Console.WriteLine("Enter key : ");
string val = Console.ReadLine();
Console.WriteLine("Enter sig: ");
string val1 = Console.ReadLine();
var receivedKey = BigInteger.Parse("0" + val, NumberStyles.AllowHexSpecifier);
var receivedSignature = BigInteger.Parse("0" + val1, NumberStyles.AllowHexSpecifier);
var receivedFinalKey = a.ReceiveKey(publicKey, new Tuple <BigInteger, BigInteger>(receivedKey, receivedSignature));
Console.WriteLine(receivedFinalKey.ToString("X"));
Console.ReadKey();
}
public CryptoSystem(Abonent a, Abonent b)
{
A = a;
B = b;
}
